X-Git-Url: http://git.subgeniuskitty.com/vvhitespace/.git/blobdiff_plain/1adfc4f47354f613475855e2cf21f6cb87043410..140262a9623b3c225a5135b9003526cb6b837926:/vv_interpreter.c diff --git a/vv_interpreter.c b/vv_interpreter.c index 8f98fec..7705319 100644 --- a/vv_interpreter.c +++ b/vv_interpreter.c @@ -11,6 +11,7 @@ #include #include #include +#include #define VERSION 1 @@ -21,10 +22,10 @@ void print_usage(char ** argv) { - printf( "Whitespace Interpreter v%d (www.subgeniuskitty.com)\n" + printf( "VVhitespace Interpreter v%d (www.subgeniuskitty.com)\n" "Usage: %s -i \n" " -h Help (prints this message)\n" - " -i Specify a Whitespace source file to interpret.\n" + " -i Specify a VVhitespace source file to interpret.\n" , VERSION, argv[0] ); } @@ -46,12 +47,38 @@ stdin_empty(void) return 1; } +void +set_terminal_mode(void) +{ + struct termios options; + tcgetattr(STDIN_FILENO, &options); + /* Create a cbreak-like environment through the following options. */ + options.c_lflag &= ~ECHO; /* Disable echoing of input characters. */ + options.c_lflag &= ~ICANON; /* Disable cooked/line-oriented mode. */ + options.c_cc[VMIN] = 1; + options.c_cc[VTIME] = 0; + tcsetattr(STDIN_FILENO, TCSANOW, &options); +} + +void +unset_terminal_mode(void) +{ + struct termios options; + tcgetattr(STDIN_FILENO, &options); + /* Undo the changes made in set_terminal_mode(). */ + options.c_lflag |= ECHO; /* Enable echoing of input characters. */ + options.c_lflag |= ICANON; /* Enable cooked/line-oriented mode. */ + options.c_cc[VMIN] = 1; /* Default value from /usr/src/sys/sys/ttydefaults.h */ + options.c_cc[VTIME] = 0; /* Default value from /usr/src/sys/sys/ttydefaults.h */ + tcsetattr(STDIN_FILENO, TCSANOW, &options); +} + void ws_die(size_t * pc, char * msg) { - printf("\n"); printf("SIM_ERROR @ PC %lu: %s\n", *pc, msg); fflush(stdout); + unset_terminal_mode(); exit(EXIT_FAILURE); } @@ -80,6 +107,10 @@ next_code_byte(uint8_t * code, size_t * pc) return code[(*pc)++]; } +/* + * In addition to returning the parsed label, this function advances the PC to + * the next instruction. + */ uint16_t parse_label(uint8_t * code, size_t * pc) { @@ -89,9 +120,24 @@ parse_label(uint8_t * code, size_t * pc) label = label << 1; if (c == ' ') label++; } + // TODO: Where should I handle attempts to access an unitialized label? + // For now, leave it undefined in a nasal demon sense. return label; } +void +populate_labels(uint32_t * labels, uint8_t * code, size_t code_size) +{ + size_t cp = 0; + while (cp <= code_size) { + if (code[cp] == '\v') { + uint16_t temp_label = parse_label(code, &cp); + labels[temp_label] = cp; + } + cp++; + } +} + void process_imp_stack(uint8_t * code, size_t * pc, int32_t ** sp) { @@ -104,13 +150,14 @@ process_imp_stack(uint8_t * code, size_t * pc, int32_t ** sp) switch (next_code_byte(code,pc)) { case ' ' : sign = 1; break; case '\t': sign = -1; break; - case '\n': ws_die(pc, "expected sign"); break; + default : ws_die(pc, "expected sign"); break; } /* Now, construct the number and push to TOS. */ /* I'm assuming the numbers are read MSb first. */ int32_t temp, number = 0; while ((temp = next_code_byte(code,pc)) != '\n') { + if (temp == '\v') ws_die(pc, "non-binary digit in number"); number <<= 1; if (temp == '\t') number++; } @@ -138,10 +185,13 @@ process_imp_stack(uint8_t * code, size_t * pc, int32_t ** sp) case '\n': stack_pop(sp); break; + default: + ws_die(pc, "malformed stack IMP"); + break; } } break; - case '\t': ws_die(pc, "malformed stack IMP"); break; + default: ws_die(pc, "malformed stack IMP"); break; } } @@ -166,6 +216,9 @@ process_imp_arithmetic(uint8_t * code, size_t * pc, int32_t ** sp) /* Multiplication */ stack_push(sp, stack_pop(sp)*stack_pop(sp)); break; + default: + ws_die(pc, "malformed arithmetic IMP"); + break; } } break; @@ -182,11 +235,11 @@ process_imp_arithmetic(uint8_t * code, size_t * pc, int32_t ** sp) temp = stack_pop(sp); stack_push(sp, stack_pop(sp)%temp); break; - case '\n': ws_die(pc, "malformed arithmetic IMP"); break; + default: ws_die(pc, "malformed arithmetic IMP"); break; } } break; - case '\n': ws_die(pc, "malformed arithmetic IMP"); break; + default: ws_die(pc, "malformed arithmetic IMP"); break; } } @@ -197,25 +250,34 @@ process_imp_flowcontrol(uint8_t * code, size_t * pc, int32_t ** sp, uint32_t * l switch (next_code_byte(code,pc)) { case '\n': /* Technically another LF is required but we ignore it. */ - printf("\n"); fflush(stdout); + unset_terminal_mode(); exit(EXIT_SUCCESS); case ' ': { switch (next_code_byte(code,pc)) { case ' ': /* Mark a location in the program. */ - labels[parse_label(code, pc)] = *pc; + if (next_code_byte(code,pc) != '\v') ws_die(pc,"expected vtab, " + "perhaps a whitespace program, rather than vvhitespace?"); + /* Jump to next instruction since labels were parsed during startup. */ + parse_label(code, pc); break; case '\t': /* Call a subroutine. */ - *((*rsp)++) = *pc; - *pc = labels[parse_label(code, pc)]; + { + size_t temp_pc = labels[parse_label(code, pc)]; + *((*rsp)++) = *pc; + *pc = temp_pc; + } break; case '\n': /* Jump unconditionally to a label. */ *pc = labels[parse_label(code, pc)]; break; + default: + ws_die(pc, "malformed flow control IMP"); + break; } } break; @@ -224,19 +286,25 @@ process_imp_flowcontrol(uint8_t * code, size_t * pc, int32_t ** sp, uint32_t * l switch (next_code_byte(code,pc)) { case ' ': /* Jump to a label if TOS == 0 */ - if (stack_peek(sp,0) == 0) *pc = labels[parse_label(code, pc)]; + if (stack_pop(sp) == 0) *pc = labels[parse_label(code, pc)]; break; case '\t': /* Jump to a label if TOS < 0. */ - if (stack_peek(sp,0) < 0) *pc = labels[parse_label(code, pc)]; + if (stack_pop(sp) < 0) *pc = labels[parse_label(code, pc)]; break; case '\n': /* Return from subroutine. */ *pc = *(--(*rsp)); break; + default: + ws_die(pc, "malformed flow control IMP"); + break; } } break; + default: + ws_die(pc, "malformed flow control IMP"); + break; } } @@ -244,9 +312,21 @@ void process_imp_heap(uint8_t * code, size_t * pc, int32_t ** sp, int32_t ** hp) { switch (next_code_byte(code,pc)) { - case ' ' : /* Store to heap */ *(*hp + *((*sp)-1)) = **sp; *sp -= 2; break; - case '\t': /* Retrieve from heap */ **sp = *(*hp + **sp); break; - case '\n': ws_die(pc, "malformed heap IMP"); break; + case ' ' : + /* Store to heap */ + { + int32_t value = stack_pop(sp); + int32_t addr = stack_pop(sp); + *(*hp + addr) = value; + } + break; + case '\t': + /* Retrieve from heap */ + stack_push(sp, *(*hp + stack_pop(sp))); + break; + default: + ws_die(pc, "malformed heap IMP"); + break; } } @@ -258,9 +338,9 @@ process_imp_io(uint8_t * code, size_t * pc, int32_t ** sp, int32_t ** hp) /* Output */ { switch (next_code_byte(code,pc)) { - case ' ' : /* Output character from TOS */ printf("%c", stack_pop(sp)); break; - case '\t': /* Output number from TOS */ printf("%d", stack_pop(sp)); break; - case '\n': ws_die(pc, "malformed output IMP"); break; + case ' ' : /* Output char from TOS */ printf("%c", stack_pop(sp)); break; + case '\t': /* Output digit from TOS */ printf("%c", stack_pop(sp)+'0'); break; + default : ws_die(pc, "malformed output IMP"); break; } fflush(stdout); } @@ -272,17 +352,15 @@ process_imp_io(uint8_t * code, size_t * pc, int32_t ** sp, int32_t ** hp) char c = getchar(); switch (next_code_byte(code,pc)) { case '\t': /* Input digit */ c -= '0'; /* fallthrough */ - case ' ' : /* Input character */ *(*hp + *((*sp)--)) = c; break; - case '\n': ws_die(pc, "malformed input IMP"); break; + case ' ' : /* Input character */ *(*hp + *(--(*sp))) = c; break; + default : ws_die(pc, "malformed input IMP"); break; } } break; - case '\n': ws_die(pc, "malformed i/o IMP"); break; + default: ws_die(pc, "malformed i/o IMP"); break; } } -/* TODO: Continue cleanup here */ - int main(int argc, char ** argv) { @@ -307,25 +385,29 @@ main(int argc, char ** argv) } } if (input == NULL) { - fprintf(stderr, "ERROR: Must specify a Whitespace source file with -f flag.\n"); + fprintf(stderr, "ERROR: Must specify a VVhitespace source file with -f flag.\n"); print_usage(argv); exit(EXIT_FAILURE); } /* - * Read just the Whitespace source code into memory. + * Read just the VVhitespace source code into memory. * We will use the array indices as addresses for the virtual PC when jumping to labels. */ size_t ws_code_size = 0; uint8_t temp_byte; while (fread(&temp_byte, 1, 1, input)) { - if (temp_byte == ' ' || temp_byte == '\t' || temp_byte == '\n') ws_code_size++; + if (temp_byte == ' ' || temp_byte == '\t' || temp_byte == '\n' || temp_byte == '\v') { + ws_code_size++; + } } rewind(input); uint8_t * ws_code_space = malloc(ws_code_size); ws_code_size = 0; while (fread(&temp_byte, 1, 1, input)) { - if (temp_byte == ' ' || temp_byte == '\t' || temp_byte == '\n') ws_code_space[ws_code_size++] = temp_byte; + if (temp_byte == ' ' || temp_byte == '\t' || temp_byte == '\n' || temp_byte == '\v') { + ws_code_space[ws_code_size++] = temp_byte; + } } fclose(input); @@ -333,6 +415,7 @@ main(int argc, char ** argv) * Setup a stack and heap. * Assume a 32-bit word size. */ + // TODO: Make everything 64-bit. int32_t * hp = malloc(HEAPSIZE*4); int32_t * sp = malloc(STACKSIZE*4); @@ -340,17 +423,20 @@ main(int argc, char ** argv) * Setup the return stack and the label array. */ uint32_t * rsp = malloc(RETURNSTACKSIZE*4); - uint32_t labels[65536]; + uint32_t labels[65536] = {0}; + populate_labels(labels, ws_code_space, ws_code_size); /* * Main Loop */ - + set_terminal_mode(); size_t pc = 0; /* Virtual program counter. Operates in the ws_code_space[] address space. */ while (1) { if (pc >= ws_code_size) { - fprintf(stderr, "SIM_ERROR: PC Overrun\n Requested PC: %lu\n Max Address: %lu\n", pc, ws_code_size-1); + fprintf(stderr, "SIM_ERROR: PC Overrun\n Requested PC: %lu\n Max Address: %lu\n", + pc, ws_code_size-1); exit(EXIT_FAILURE); + unset_terminal_mode(); } /* Decode the IMPs */ @@ -382,6 +468,7 @@ main(int argc, char ** argv) } } break; + default: ws_die(&pc, "unexpected VTab"); break; } } @@ -389,4 +476,5 @@ main(int argc, char ** argv) printf("Program executed.\n"); exit(EXIT_SUCCESS); + unset_terminal_mode(); }